Stock Market Sectors

The U.S. stock market is organized into 11 sectors under the Global Industry Classification Standard (GICS), a framework developed jointly by S&P Global and MSCI. This classification system groups 30,566+ publicly traded companies by their primary business activity, making it possible to compare performance, identify trends, and build diversified portfolios across the entire market.

Sector analysis is one of the most effective tools available to investors. By tracking how capital flows between sectors, you can identify which areas of the economy are gaining momentum and which are losing favor. Cyclical sectors like Technology and Consumer Discretionary tend to outperform during economic expansions, while defensive sectors like Utilities and Consumer Staples often hold up better during downturns.

Each sector page on Stock Expert AI provides AI-powered MoonshotScore ratings, real-time price movements, top gainers and losers, industry breakdowns, and comprehensive stock tables. The MoonshotScore rates each U.S. common stock against its sector peers across five pillars—business quality, financial safety, valuation, growth durability, and momentum—while ETFs, OTC names, and foreign listings use a legacy nine-signal model, surfacing the strongest stocks within each sector.

Currently, the largest sector by company count is Financials with 13,532 stocks, while the smallest is Utilities with 655 stocks. Use the sector pages below to drill into each area of the market.

Stock Expert AI evaluates every publicly traded U.S. stock using the MoonshotScore, a proprietary 0–100 composite rating. U.S.-listed common stocks are scored against their sector peers across five pillars: business quality, financial safety, valuation, growth durability, and momentum. ETFs, OTC names, and foreign listings use a legacy nine-signal quantitative model spanning growth, margins, cash position, insider activity, liquidity, momentum, and news sentiment.

Price data is sourced from Financial Modeling Prep (FMP) with Yahoo Finance as a fallback. Fundamental data comes from SEC filings, FMP, and Alpha Vantage. Sentiment signals are derived from aggregated analyst ratings and news flow. All metrics refresh during market hours; after-hours data reflects the most recent closing values.

Sector and industry classifications follow the Global Industry Classification Standard (GICS), the same taxonomy used by S&P and MSCI. Companies are assigned to one of 11 sectors and further classified into 50+ industries based on their primary revenue source.